Frogs and Toads of Illinois
If you are looking to identify a specific frog and can’t figure it out from the page, you can check my Frog Identification and see how to contact me about helping you out.
Frogs
True Frog Family – Ranidae
The True Frogs are your typical frogs that you find along the shores of a lake or pond.
American Bullfrog (Rana catesbeiana)
Common Name: American Bullfrog
Scientific Name: Rana catesbeiana
Location: Statewide
Breeding Season:
The American Bullfrog is the largest frog in the state. They are found near permanent bodies of water such as large ponds, streams, and lakes. Once the males of the species reach sexual maturity, their throats turn bright yellow. They are very similar to Green Frogs but they don’t have a dorsal ridge down their back. It wraps around their tympanum.
Common Name: Green Frog
Scientific Name: Rana clamitans
Location: Statewide besides southcentral Illinois
Breeding Season:
The Green Frog looks very much like the American Bullfrog but it’s a tad smaller. It has a dorsal ridge that runs down its back but they are incomplete and do not reach all the way.
Common Name: Wood Frog
Scientific Name: Rana sylvatica
Location: Near the northern, eastern, and southern borders of the state
Breeding Season:
The Wood Frog is one of the most widespread frog in the United States but it’s a little rare in Illinois. It’s listed by the states as a Species in Greatest Need of Conservation. They are a small to medium sized frog. They vary in color from brown, silver, or red and they have dark “raccoon” eyes. When winter comes, the Wood Frog can freeze completely solid and then unthaw in spring. They start to breed once the ice is off the ponds in late March / early April. After breeding season, they are often found in the woods, far away from any water bodies.
Common Name: Crawfish Frog
Scientific Name: Rana areolatus
Location: Southern part of the state
Breeding Season:
The Crawfish Frog gets its name from living in crawfish holes. Its has skin folds on the side and a small typanum. It also has a pair of vocal sacs for calling.
Common Name: Plains Leopard Frog
Scientific Name: Rana blairi
Location: Everywhere besides the northern border
Breeding Season:
Northern Leopard Frog (Rana pipiens)
Common Name: Northern Leopard Frog
Scientific Name: Rana pipiens
Location: Northern part of the state
Breeding Season:
The Northern Leopard Frog is a medium to large species of semi aquatic species of frog. They vary in color from dark brown to slim green with fairly large spots all over their body.
Common Name: Southern Leopard Frog
Scientific Name: Rana sphenocephalus
Location: Southern half
Breeding Season:
The Southern Leopard Frog has a white spot on its tympanum which can help differentiate the species from the other two. The Plains Leopard Frog is different from the Southern and Northern Leopard Frog because of its dorsal ridge. The Plains Leopard Frogs has a break and an indent near its butt while the North and South Leopard Frog just has a straight line.
Common Name: Pickeral Frog
Scientific Name: Rana palustris
Location: Northern and western borders of the state
Breeding Season:
The Pickerel Frog is a medium to large sized frog. Their dorsal ridge runs down from their eye to their back and inside there is rectangular boxes.
Tree Frog Family – Hylidae
Cricket Frogs – Acris
Common Name: Blanchard’s Cricket Frog
Scientific Name: Acris blanchardi
Location: Statewide
Breeding Season:
The Blanchard’s Cricket Frog is the only cricket frog in the state. Its skin is relatively more rough than the other tree frogs in the state. It also has no distinct markings.
Tree Frogs – Hyla
Eastern Gray Tree Frog (Hyla versicolor) and Cope’s Gray Tree Frog (Hyla chrysoscelis)
Common Name: Eastern Gray Tree Frog
Scientific Name: Hyla versicolor
Location: Everywhere besides southern tip
Breeding Season:
Common Name: Cope’s Gray Tree Frog
Scientific Name: Hyla chrysoscelis
Location: Statewide
Breeding Season:
The Gray Tree Frogs are nearly identical besides their calls and chromosome numbers. These medium sized frogs can be found perched in trees or on the side of your house. They are not always gray in color and can be green. They have yellow or orange coloration on their back legs.
Here is a short video of a few Eastern Gray Tree Frog calling

Common Name: Bird-Voiced Tree Frog
Scientific Name: Hyla avivoca
Location: Southern tip of the state
Breeding Season:
The Cope’s Gray Tree Frog, the Eastern Gray Tree Frog and the Bird-Voiced Frog look very much a like. The difference is the coloration on the inner thigh. Cope’s Gray Tree Frog and Gray Tree Frog has brighter orange color on the thigh while the Bird-Voiced Frog is more greenish-yellow.

Common Name: Green Tree Frog
Scientific Name: Hyla cinerea
Location: Southern tip of the state
Breeding Season:
The Green Tree Frog does not have any coloration on its inner legs. It has a white line that runs down its side.
Chorus Frogs – Pseudacris
Spring Peeper (Pseudacris crucifer)
Common Name: Spring Peeper
Scientific Name: Pseudacris crucifer
Location: Statewide
Breeding Season:
The Spring Peeper is a small chorus frog that can often be found on forest floor or low on trunks of trees. They can be hard to find due to their small size, however, in spring when they come to temporary ponds to breed, they are easier to find. They can be distinguished from Boreal Chorus Frog and Cricket Frog due to their x on their back.

Boreal Chorus Frog (Pseudacris maculata)
Common Name: Boreal Chorus Frog
Scientific Name: Pseudacris maculata
Location: Statewide besides the southern tip
Breeding Season:
The Boreal Chorus Frog is a small sized Chorus Frog, ranging from brown, red, tan, to olive in color. They have 3 stripes down their back with middle stripe on its back is occasionally broken. It also has really small legs.
Common Name: Western Chorus Frog
Scientific Name: Pseudacris triseriata
Location: Southern half
Breeding Season:
The Western Chorus Frog’s three stripes on its back are rarely broken.
Common Name: Upland Chorus Frog
Scientific Name: Pseudacris feriarum
Location: Southern tip
Breeding Season:
The Upland Chorus Frog’s stripes on it’s back are often broken up and can appear as spots.

Common Name: Illinois Chorus Frog
Scientific Name: Pseudacris illinoensis
Location: Western border area
Breeding Season:
The Illinois Chorus Frog does not have a white line that extends off the lips while the other chorus frogs do.
Toads
True Toad Family – Bufonidae
The family Bufonidae is known for the toxins / poison they produce called Bufotoxins. It is a bad idea to try to eat these guys.
American Toad (Anaxyrus americanus)
Common Name: American Toad
Scientific Name: Anaxyrus americanus
Location: Statewide
Breeding Season:
Common Name: Fowler’s Toad
Scientific Name: Anaxyrus fowleri
Location: Everywhere besides the northern border
Breeding Season:
The American Toad and Fowler’s Toad look fairly similar. The Fowler’s Toad has their cranial crest and the parotoid gland touch while the American Toad’s cranial crest and parotoid gland do not touch or are connected by a spur. The American Toad has a more speckled belly while the Fowler’s Toad has a clear, white one.
Spadefoot Toads – Scaphiopodidae

Common Name: Eastern Spadefoot Toad
Scientific Name: Scaphiopus holbrookii
Location: Southern tip
Breeding Season:
The Eastern Spadefoot Toad is the only Spadefoot toad in the state so it can easily be identified because of the spade on its back legs.
Narrowed Mouth Toad Family – Microhylidae
Common Name: Eastern Narrow Mouthed Toad
Scientific Name: Gastrophryne carolinensis
Location: Southern tip
Breeding Season:
The Eastern Narrow Mouthed Toad is the only narrow mouthed toad in the state. One could potentially misidentify it has a Spadefoot toad because of its burrowing lifestyle but the head is narrower and there’s no spade on the back feet.
Thank you so much for your wonderful information. We have 18 acres with a small stream, mostly oak and black walnut woods. We will be building a couple of ponds to cut back on errosion during thunderstorms where the stream curves … how can I get turtles and frogs to live on my property? We have plenty of insects for them. Located in East Moline, Il. I saw a toad in the flower garden once, never a snake (thank goodness), frog, or turtle. Thank you
When do frogs come out of hibernation in Illinois?
when the snow starts to seriously melt
If I send a picture of the toad that lives on my deck, can you tell me what kind it is?
yes
I’m From Minnesota and am a beatboxer. My fascination is With the sounds that Species make. I have a video on the Western chorus Frog sound. I make tutorials for animal sounds including our Species.. Most of which are available on YouTube My channel is Two Sounds at Once. I have a decent grasp on Minnesota’s Species calls and have a video on them. I also am trying to Cover many of the surrounding states species. I have presented at our Local Reptile and Amphibian Zoo. I’m not a typical beatboxer in fact more of a Bioboxics or bioboxer. Bio is prefix for biological and boxics is the beatbox aspect of making a sound. I’m pioneering this technique and hope also to get more kids and teens involved in conservation. I also hope to have Bioboxics be a form of curriculum and study to be respected with linguistic and biological communities. I hope you have fun as the summer winds down.
Here are some links if your interested.
https://www.bing.com/videos/search?q=Two+sounds+at+once+youtube&view=detail&mid=6E700D2AB1BB68AA931F6E700D2AB1BB68AA931F&FORM=VIRE
https://www.bing.com/videos/search?q=Two+sounds+at+once+youtube&view=detail&mid=D0EE6B99F26BAD7A2483D0EE6B99F26BAD7A2483&FORM=VIRE
My Writings
https://www.amazon.com/Bioboxics-Beginners-Michael-Bolton-JR/dp/1717393640
https://www.amazon.com/Two-Sounds-Once-Michael-Bolton/dp/1537008765
Best regards,
Michael Bolton Jr.